Adj.: Means extremely super.
Came from the word super. Pronounced: Z'oo'per
Thats zuper cool.
Yeah dude, that's sicky gnar gnar.
A Zuper is usually a strange, random, crazy kind of a guy. People call him Zuper because he's not-quite/more-than super. Generally musically inclined and very much a geek in every way possible.
Chandler: Wow! Zuper can really sing!
Mike: Yeah, but notice he's singing a song about D&D...